Producing Soybeans Without Tillage

Growing soybeans in Ohio without tillage has become both practical and profitable, and often reduces or eliminates some tillage related problems. Time savings accrued by eliminating tillage can be invested in earlier and more careful planting or the planting of more acres. Maintenance of crop residue on the soil surface reduces soil crusting, which can lead to better and more uniform seedling emergence; improved yields on some soils; and reduced needs for rotary hoeing, cultivating and replanting. In addition, no-till systems do not bury weed seeds, reducing the germination potentials of some species, particularly “large seeded” broadleaf weeds. Finally, use of no-till systems can prolong the life of surface drainage improvements, particularly on flatter fields. 

When planting no-till soybeans, growers should pay attention to soil drainage; planting procedures; crop rotation options; and disease, insect, and weed control. While the improper management of any of these factors will reduce yields in tillage systems, their effects can be much more adverse with no tillage. The following problems are created by removing tillage from the crop production system and important adjustments must be made to offset those negative effects: 

1. Cooler soil temperatures slow germination, emergence and early growth. 

Because the soil is warmer at the surface than at the 1.5-inch planting depth, the solution is to plant shallow (1 inch), but in moist soil. The warmer soil temperatures at shallow depth will enable seeds to germinate and emerge earlier and, in effect, produce a closed leaf canopy and get to the reproductive stage sooner. The use of narrow rows (7.5 inches) will compensate for the slower early growth associated with no-till production. Good seed to soil contact and the use of high quality seed treated with the appropriate fungicides promotes the rapid emergence of a healthy crop. Slower planting speed will allow the planting tool to space seed more uniformly in the row and at a more uniform depth so that seeding rates can be reduced, thus lowering production costs. 

2. Root rot diseases are much more severe due to a wetter and cooler soil environment. 

Two actions can increase plant stands and improve root health: 

Select varieties with high levels of Phytophthora partial resistance that will give a good level of protection against all strains of Phytophthora, and then treat the seed to protect the seedling from Phytophthora and Pythium root rot until the partial resistance mechanism takes effect just after emergence. 

Another strategy is to use soybean varieties that have one or more Rps resistance gene(s) for control of Phytophthora root rot. Other broad spectrum fungicides will control other diseases that damage the root system and lower stand counts. No-till is not advised for poorly drained fields, and do not plant when the soil is too wet for shallow tillage. Tillage or planting operations on a wet soil compacts the soil particles which inhibits the proper development of root systems and thus reduces yield. For additional information on controlling soybean diseases see: agcrops.osu.edu. 

3. Heavy crop residue and more dense soil can interfere with proper seeder function and lead to poor distribution, poor placement of seed and lack of adequate depth control. 

Spreading crop residue evenly when harvesting will help keep the field surface uniformly covered with residue and at uniform moisture so the entire field is ready to plant at the same time. Due to its fineness, wheat residue keeps the soil colder and wetter than other residues because it provides nearly 100 percent cover and its light color reflects sunlight. Remove wheat straw when possible and partially incorporate the stubble with a disk to promote its degradation. 

Try not to plant on old corn rows since old corn roots interfere with depth control and seed placement. Maintain a down pressure of at least 200 pounds on each row opener to penetrate hard soil areas and use a good depth control mechanism to maintain the proper seeding depth in soft soil. A residue cutting coulter will prevent hair pinning of residue into the seed furrow which interferes with seed placement, and it will also loosen some soil that the furrow closers can use to cover seed and improve seed-to-soil contact.